A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station (BS), and a plurality of subscriber units (SUs). The signals transmitted between the BS and SU use spread-spectrum modulation. The improvement method for maintaining control of power from an SU to a BS comprises sending from the subscriber unit, using spread-spectrum modulation, a SU-spreading code, and detecting, at the BS, the SU-spreading code from the SU. In response to detecting the SU-spreading code at the BS, a BS-spreading code is sent to the SU, using spread-spectrum modulation. At the SU, if the BS-spreading code is detected, then transmit power of the SU is reduced. If the BS-spreading code is not detected at the SU, then transmit power of the SU is increased.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An improved method for maintaining control of power from a subscriber unit (SU) to a base station (BS), comprising the steps of: (a) sending from the SU to the BS, using spread-spectrum modulation, a SU-spreading code on a status channel; (b) detecting, at the BS, the SU-spreading code from the SU; (c) sending, from the BS to the SU, using spread-spectrum modulation, in response to detecting the SU-spreading code, a BS-spreading code on a checkup channel; (d) detecting, at the SU, the BS-spreading code on the checkup channel; (e) reducing, at the SU, in response to detecting the BS-spreading code, transmit power of the SU; and (f) increasing, at the SU, in response to not detecting the BS-spreading code, transmit power of the SU.
2. The method improvement as set forth in claim 1 , with step (a) further including the step of periodically sending from the SU to the BS, using spread-spectrum modulation, the SU-spreading code, having a symbol length, on the status channel.
3. The method improvement as set forth in claim 2 , with step (c) further including the step of sending, from the BS to the SU using spread-spectrum modulation, in response to detecting the SU-spreading code, the BS-spreading code having a symbol length on the checkup channel.
4. The method improvement as set forth in claim 1 , with step (a) further including the step of periodically sending from the SU to the BS using spread-spectrum modulation, the SU-spreading code, having a symbol length, on the status channel, and with step (c) further including the step of sending, from the BS to the SU, using spread-spectrum modulation, in response to detecting the SU-spreading code, the BS-spreading code having a symbol length on the checkup channel.
5. The method improvement as set forth in claim 1 , further including the step of repeating steps (a) through (f).
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
December 21, 2000
March 16, 2004
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